Alrighty - I've had a chance to screw with GPS hooked up to Route 66, albeit only for a little bit. The functionality is VERY minimal. Basically, it will show you where on the map you are, and it will continuously center the map to your current location. Supposedly you can use your current location as a starting point for a new route, but I haven't had time to figure out how to do it. That's about the extent of the GPS-supported functionality in Route 66. It won't warn you of an upcoming turn, much less give you a voice prompt. It is, however, useful and functional - it would be really nice to have on an out-of-town car trip...